The National Metrological Institute (NMI) or its Designated Institutes (DI) represent the top level of the traceability chain for calibrations. They maintain the highest national measurement standards and ensure that the measurements correspond to the international system of units SI. NMIs and DIs participate in international comparative measurements with other NMIs and cooperate in technical committees to ensure that they are the top reference for measurement variables.
The measurement uncertainties of NMIs or DIs do not (or hardly) exceed those of accredited top calibration laboratories but can also be provided for special calibration tasks as part of the internationally agreed calibration options (CMC data) published in the BIPM (Bureau International des Poids et Mesures).
Calibration carried out by NMIs and DIs are very extensive, do not address the frequent calibration tasks in industrial measurement, and are therefore only of interest in international comparisons among accredited calibration laboratories.
E+E Elektronik, as designated Institute of the Republic of Austria / BEV for humidity, dew point, air velocity and gas concentration CO₂, is authorised to carry out calibrations at the level of a National Metrological Institute.
Institute for Gas
With 02.07.2014 the designated laboratory of E+E Elektronik has been authorized by the Director of the BIPM to use the CIPM MRA logo. The CIPM MRA logo can therefore be displayed on all calibration and measurement certificates of the designated laboratory covered by Calibration Measurement Capabilities (CMCs) published in Appendix C of the CIPM Mutual Recognition Arrangement (MRA) and listed in the BIPM key comparison database (KCDB).
Currently, for the designated laboratory of E+E Elektronik (BEV / E+E) the following entries are listed in the BIPM key comparison database:
The MRA has been drawn up by the CIPM, under the authority given to it in the Metre Convention. National Metrology Institutes (NMIs) from 54 states are signatories to the MRA, including NIST (US), NPL (UK), PTB (DE), BEV (AT) etc.:
E+E Elektronik is as Designated Laboratory on behalf of the Federal Office of Metrology and Surveying (BEV) for humidity, dew point, air flow velocity and gas concentration CO₂ implicitly co-signatory of the MRA and listed under "Austria, Designated Institutes".
The CIPM MRA key objectives are to:
- establish the degree of equivalence of national measurement standards maintained by NMIs;
- provide for the mutual recognition of calibration and measurement certificates issued by NMIs;
- provide governments and other parties with a secure technical foundation for wider agreements related to international trade, commerce and regulatory affairs.
Within this arrangement, National Metrology Institutes declare their Calibration and Measurement Capabilities (CMCs) and have these CMCs rigorously assessed by international experts. They also have to demonstrate their measurement competence by the mandatory participation in appropriate key and supplementary comparisons and by operating a quality system in compliance with EN ISO/IEC 17025 . When these criteria are met the CMCs can then be published on the BIPM website. The CMC tables can be considered equivalent to the scope of accreditation table of a laboratory accredited under EN ISO/IEC 17025.
Acceptance of Calibration Certificates
A certificate issued by a laboratory under the CIPM MRA can be accepted by assessors from Conformity Assessment Bodies with the highest level of confident.